Determination of the rates of formation and hydrolysis of the Schiff bases formed by pyridoxal 5′-phosphate and hydrazinic compounds

✍ Scribed by Gerardo R. Echevarrı́a; Andrea Basagoitia; José G. Santos; Francisco Garcı́a Blanco

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 144 KB
• Volume: 160
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/s1381-1169(00)00266-1

✦ Synopsis

The macroscopic rate constants of formation k and hydrolysis k for the reactions of pyridoxal 5 -phosphate PLP 1 2 Ž . Ž Ž . with hydrazine PLP-HY system , carbidopa a-hydrazino-a-methyl-b-3,4-dihydroxyphenyl propionic acid, PLP-CD sys-. Ž . Ž tem , hydralazine 1-hydrazinophthalazine, PLP-HL system and isoniazid 4-pyridinecarboxylic acid hydrazide, PLP-ISO . system were fitted to a kinetic scheme that considers the different ionic species present in the medium, their protonation Ž i . Ž i . constants, and their individual rates of formation k and hydrolysis k . The results obtained for the molecules bearing the 1 2 Ž . hydrazine group are compared with those for the reactions of PLP with n-hexylamine PLP-NHA system and poly-L-lysine Ž . PLP-LYS system . Some structural effects on the individual rate constants are also examined.